• Korean journal of applied entomology
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• v.32 no.2
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• pp.225-235
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• 1993

This study was carried out to investigate effects of diazinon, an organophosphate, and nicotine, a plant~originated toxic chemical, on larval mortality and activity of cytochrome P-45D monooxygenases, a major detoxifwation enzyme system, in Helicoverpa assulta and Spodoptera exigua. Diazinon treatment gave a higher mortaliLy to H. assulta larvae than S. exigua larvae. In contrast to the case of diazinon, nicotine caused a higher mortahty to S. exigua than to H. assulla larvae. It was partly due to the fact that nicotine induced the actiVIty of midgut cytochrome P-450 monooxygenases (MFO) more than diazinon did in If assulta larvae. When If. aSSlllta larvae were reared on their host p\am. NicotwlIa tuoocum leaves, other componentS were mostly metabolized with the exception of dietary nicotine.

• Korean journal of applied entomology
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• v.31 no.4
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• pp.329-337
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• 1992

Studies were carried out to investigate changes of lipid and carbohydrate contents in the hemolymph of the Oriental tobacco budworm(Helicoverpa assulta (Guenee» adults during flight and hormonal effects on mobilization of energy sources in the hemolymph. During a few minutes after flight, both sexes showed a rapid increase in lipid content and the high level was maintained for about 2 hours. But carbohydrate content in the hemolymph during flight showed almost no change but a slight increase seen during the first 10 min of flight in males only. Synthetic adipokinetic(Lom-AKH- n), hypertrehalosemic(Bld-HrTH) hormones and brain/ corpora cardiaca extract of H. assulta adult elevated lipid and carbohydrate contents in hemolymph and the effect was much more pronounced for lipid. These results suggested that lipid is a main fuel for flight activity and lipid mobilization is under the hormonal control. And this study showed that both adipokinetic and hypertrehalosemic factors may exist in H. assulta and these factors may have similar structures to those of Mas-AKH, Hez-HrTH, Lom-AKH- n or Pea-HrTH.